Determination of the number of wounded nucleons in Pb+Pb collisions at 158 A GeV/c

The charged particle multiplicity distributions measured by two experiments, WA97 and NA57, in Pb+Pb collisions at 158 A GeV/c have been analyzed in the framework of the wounded nucleon model (WNM). We obtain a good description of the data within the centrality range of our samples. This allows us to make use of the measured multiplicities to estimate the number of wounded nucleons of the collision

Strange particle production in p-Be, p-Pb, Pb-Pb at 158 A GeV/c (WA97 experiment)

The CERN experiment WA97, which studies strange particle production at central rapidity in Pb-Pb, p-Pb, p-Be collisions at 158 A GeV/c, has already reported a pronounced enhancement of hyperon production. This is considered a sensitive signature for a phase transition to a new state of matter - the Quark Gluon Plasma (QGP). A comprehensive study, including the most recent results, of yields and transverse mass spectra of K-S(0), Lambda, Xi (-), Omega (-) (and antiparticles) and negative particles as a function of the number of nucleons partecipating in the collisions is presented

Strange particle production p-Be, p-Pb, Pb-Pb at 158 A GeV/c (WA97 experiment)

The CERN experiment WA97, which studies strange particle production at central rapidity in Pb-Pb, p-Pb, p-Be collisions at 158 A GeV/c, has already reported a pronounced enhancement of hyperon production. This is considered as a sensitive signature for a phase transition to a new state of matter-the quark gluon plasma (QGP). A comprehensive study, including the most recent results, of yields and transverse mass spectra of K/sub S//sup 0/, Lambda , Xi /sup -/, Omega /sup -/ (and antiparticles) and negative particles as a function of the number of nucleons participating in the collisions is presented. (11 refs)

Strangeness enhancement at midrapidity in Pb-Pb collisions at 158 A GeV/c: A comparison with VENUS and RQMD models

Recently the WA97 Collaboration has measured K-S(0), Lambda, Xi, Omega and negative particle yields and transverse mass spectra at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c. These results are compared with the predictions of two of the most widely used event generators for heavy-ion collisions: VENUS 4.12 and RQMD 2.3. Both models predict that enhancement, increase with the strangeness content of the particle. They fail, however, to reproduce completely the measured values of yields at central rapidity. In particular, for multistrange particles, VENUS fails: to reproduce both the p-Pb and the Pb-Pb data. while RQMD works for p-Pb collisions but seems to be unable to reproduce the Omega data in Pb-Pb collisions. Moreover, the predicted behavior for strangeness production as: a function of the centrality of the collision appears to be different from the observed behavior

Production of strange and multistrange hadrons in nucleus-nucleus collisions at the SPS

We report the main results from experiment WA97 on the production of strange and multistrange hadrons at midrapidity in Pb+Pb, p+Pb and p+Be collisions at 158 A GeV/c. A comparison with some of the available models is presented

Enhancement of strange and multi-strange baryons in central Pb-Pb interactions at 158 GeV/c per nucleon

Strange and multi-strange baryon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a Quark-Gluon Plasma takes place. The production yields: and transverse mass spectra of strange and multi-strange baryons and anti-baryons are presented for lead-lead interactions at 158 GeV/c per nucleon. Yields and transverse mass spectra from proton-lead and proton-beryllium interactions, where no phase transition is expected, are also presented and compared to those from lead-lead interactions